Re: Does anyone know anything about "Modulation Depth"? (Philips PM5680)
What you have there is the modulator rack from a full broadcast TV transmitter.
It takes baseband video and baseband sound signals and creates an IF signal having both video and sound modulated carriers.
From this unit, the IF signal goes off to be mixed with a local oscillator to create a signal on the intended channel. Filtering is needed to remove the image product. and the rest is power amplification with harmonic filtering.
Everything after this unit has to be carefully kept linear.
The spare slot is either for a second analogue sound modulator for analogue stereo (or dual language) service. It could also be for a NICAM modulator for digital sound.
The VSB filter means vestigial sideband. Broadcast TV has the sideband energy around the vision carrier trimmed asymmetrically so one sideband is more extensive than the other.
So, what you have is fixed frequency and not on any used TV channel frequency. You need some more hardware to get there.
David
__________________
Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done
|